1. Field of Invention
The present invention belongs to the technical field of mobile communication, and relates to a spectrum allocation method, more particularly relates to a spectrum allocation method for small cell network.
2. Description of Related Arts
LTE (Long Term Evolution) and LTE-A (LTE-Advanced) systems provided by the 3rd Generation Partnership Project (3GPP) are evolutional technologies of GSM and UMTS cellular radio systems. It may provide higher spectrum efficiency and smaller network delay, so as to make more efficiently use of spectrum resources. The conventional cellular network provides service to the user by using a Macro Base Station (MBS), but with the change in business requirements, the new generation of wireless communication system has increased new form of small cell network, e.g., Microcell, Picocell and Femtocell, etc., accordingly, as well as new network access points (also called as network nodes) to provide service for different business requirements, and to provide favorable coverage for local area).
The coexisting of new network nodes with Macro-cellular network enables to solve the coverage problem of local area, and to increase data rate. The network nodes in one network share a section of spectrum resource, and each network node may use a number of spectrum resource collections, such as resource block (RB), sub-channel, component carrier (CC), etc. However, due to the lack of centralized control device, it unable to proceed network programmer as the conventional cellular network, and some network nodes (such as small cell) exist by self-organization, thereby causing the interference among different transmission links of network nodes and the decrease of spectrum efficiency; at the same time, when users turn on or off those devices, the topology of the network will dynamic change, then the existing nodes in the network should adapt to the change, as a result, the spectrum allocation of the dynamic network needs to be deeply investigated.
Currently, some scholars have investigated the distributed spectrum allocation algorithm of the dynamic network, and have provided various methods based on game theory. For example, in a non-cooperative game theory-based resource allocation algorithm, each network node may autonomously obtain spectrum resource according to the corresponding utility function, which can be autonomously set according to different optimization goals, i.e., number of resources, throughput and the like. However, those non-cooperative game methods need a certain iterations to achieve equilibrium, and that there is still a performance gap when compared with the corporation-based algorithm. Likewise, some scholars provides a coalition game-based resource allocation algorithm, in which by sending coalition formation requests (CFR), the new added network nodes request the original nodes release spectrum resource for its use; therein, the new added nodes determine the resource allocation of both themselves and those existing neighbor modes, thus the equality among network nodes can not be maintained.